Shaped roller for a profiling line

ABSTRACT

A shaped roller for a profiling line, comprising a conical portion ( 2 ) and an end portion ( 3 ), concentric with respect to a rotating axis (Z), wherein the conical portion ( 2 ) is equipped with a vertex section ( 23 ), and wherein the end portion ( 3 ) has a greater diameter than the vertex section ( 23 ) that defines a shoulder from the surface of the first conical portion ( 2 ).

The present invention relates to a shaped roller for a profiling line for tubes.

In particular, the invention relates to a shaped roller for profiling lines for tubes having a polygonal section, for example rectangular or square.

As is known, a profiling line allows a tubular profiled element to be produced starting from a steel strip which is progressively bent back in line about a longitudinal axis thereof until it assumes a tubular conformation wherein the longitudinal edges of the strip are arranged alongside one another in the upper zone of the profiled element. For this purpose a profiling line substantially comprises a series of bending units, arranged in succession, each of which comprises two or more profiling rollers. The progressive bending of the profiled element takes place by making the strip pass through the rollers of the various bending units which, by contact, progressively deform it. The strip slides continuously through the bending units, being progressively deformed.

Still in line, i.e. while the profiled element is continuously advancing, the longitudinal edges are welded together. The profiled element is subsequently cut into portions of a pre-established length, according to known processes. The whole production is performed in line, i.e. while the profiled element is continuously advancing.

For realising a polygonal section tube, for example rectangular or square, the bending of the strip initially takes place by the operation of rollers that are located at the points in which the corners of the profiled element are to be realised. Such rollers are positioned above and below the strip, at the corners that will progressively form. On the lower or external side of the strip rotating rollers are positioned which exert an opposite pressure to the pressure exerted by the discs. Discs and rollers are aligned in succession along the longitudinal axis of the strip, supported by a support structure which can assume various configurations. When advancing the strip through the rollers and the discs a progressive bending is achieved about the longitudinal axis, up to obtaining a profiled element that is closed and tube-shaped. The closing of the tube takes place in a terminal portion of the line, along which the two opposite edges of the strip are brought side-by-side with one another and then welded in line, for example by induction or high-frequency welding, in a known way in the sector.

With reference to the production of quadrangular-section tubes, the terminal portion of the line which produces the closing of the profiled element generally comprises a plurality of rollers, arranged outside the profiled element. The rollers are positioned outside the profiled element as, physically, a sufficient space is not available to enable an internal location of sufficiently sturdy rollers. The orientation of the various rollers, which can be adjustable, varies progressively along the terminal portion of the line, for progressively guiding the profiled element to the closing step. The profiled element reaches such terminal portion when it has a substantially U-shaped bent section defined by a horizontal lower side, two sides that diverge from one another in an upwards direction, and two upper sides inclined upward so as to be converging towards each other. The two upper sides are destined to flank one another in a horizontal position, to define the upper side of the section.

The various rollers are grouped in operating units, also known as cages, each of which comprises a support frame for a determined number of rollers. For the profiling of rectangular- or square-section tubes, each cage generally comprises a lower roller, with a horizontal rotating axis, two lateral rollers, with rotating axes parallel to the sides of the profiled elements and diverging from one another in an upwards direction, and two upper rollers, which can be conical or cylindrical; in the last case with the rotating axes converging to each other in an upwards direction. Along an advancement direction of the line, the rotating axes of the lateral rollers of the various cages progressively incline towards a vertical direction. The rotating axes of the various upper rollers, or the taper thereof in a case where they are realised in a conical form, progressively incline towards a horizontal direction.

To enable obtaining the correct inclination of the various rollers, each cage must be provided with complex adjustment devices, which enable varying the inclination and the position of the rollers at least on a vertical plane. The activating of these adjustment devices can be considerably laborious, and often requires the use of complex set-up software.

Furthermore, the rollers at present used, associated to the respective cages, often do not realise a correct closure of the profiled element. In particular, the two upper sides are not always arranged perfectly coplanarly, with the edges perfectly flanked to one another, so that it is necessary to perform very accurate adjustments of the positions of the various rollers.

Furthermore, the rollers at present used do not enable precisely realising the fillet radii required between the sides of the profiled element. This is because, during the closing step of the profiled element, the upper edges of the profiled element can slide in an undesired way on the surfaces of the upper rollers.

The object of the present invention is to disclose a shaped roller for profiling lines for tubes which enables obviating the drawbacks summarised.

An advantage of the roller according to the present invention in that it facilitates the correct closing of the profiled element, drastically reducing the need to adjust the position of the various rollers.

Another advantage of the roller according to the present invention is that it enables very precisely obtaining the fillet radii required between the various sides of the profiled element.

A further advantage of the roller according to the present invention is that it significantly prevents or limits any tendency of the profiled element to twist about the longitudinal axis thereof.

Further characteristics and advantages of the present invention will become more apparent in the following detailed description of an embodiment of the present invention, illustrated by way of non-limiting example in the attached figures, in which:

FIG. 1 shows a schematic view of two shaped rollers according to the present invention;

FIG. 2 shows a cross-section view of a quadrangular-section profiled element;

FIG. 3 shows a schematic view of a portion of the finishing portion of a profiling line, in which three operating units according to the present invention are present;

FIG. 4 shows a front view of an operating unit according to the present invention;

FIG. 5 shows a front view of an operating unit according to the present invention, in an alternative embodiment.

FIG. 3 schematically illustrates a portion of the finishing portion of a profiling line. In particular three operating units (M) are illustrated, each provided with two shaped rollers (1) according to the present invention. The operating units (M) are aligned along a longitudinal direction (Y) which also defines the longitudinal axis of the profiled element (P).

The profiled element (P) that enters each operating unit presents, on a section carried out with a plane perpendicular to the longitudinal direction (Y), a lower side (B), two sides (S1, S2) and two upper sides (T1, T2) inclined upward so as to be converging towards each other (FIG. 2). The lower side (B) is substantially horizontal. The sides (S1, S2) can be divergent in an upwards direction, as in the represented case. Proceeding progressively along the finishing portion through the various operating units, the sides (S1, S2) assume a position progressively closer to the vertical axis, while the upper sides progressively approach a horizontal position.

As illustrated in FIG. 1, the shaped roller according to the present invention comprises a conical portion (2) and an end portion (3), concentric with respect to a rotating axis (Z). The rotating axis (Z) is preferably though not necessarily horizontal and is perpendicular to the longitudinal direction (Y). The conical portion (2) is provided with a vertex section (23), in which the diameter is minimal. The end portion (3) has a greater diameter than the vertex section (23). In this way, the end portion (3) defines a shoulder from the surface of the first conical portion (2).

The conformation of the shaped roller (1) according to the present invention provides important advantages. The conical portion (2) is predisposed to enter into contact with an upper side (T1) of the profiled element. As it enters into contact with the conical portion (2), such upper side (T1) assumes an inclination that is substantially coincident with the taper of the conical portion (2). On the contrary to what happens with the cylindrical rollers at present available, which have to be arranged with the rotating axis inclined and adjustable, the shaped rollers according to the present invention can be arranged with the rotating axis horizontal. Furthermore, the end portion (3), provided with a greater diameter with respect to the vertex section (23), defines a shoulder in contact with which the edge of the upper side (T1) is positioned, as schematically illustrated in FIG. 1. Owing to the end portion (3), the upper side (T1) does not slide on the surface of the conical portion (2) and can be bent thereby with a high degree of precision, enabling predetermined fillet radii to be realised with the side (S1).

The shaped rollers (1) of the various operating units have a taper that gradually decreases in the advancement direction of the profiled element, up to reaching a very small taper or becoming substantially cylindrical so as to bring the upper sides (T1, T2) into a position that is very close to a horizontal position. Generally, downstream of the finishing portion there is a welding group that, by means of an upper cylindrical roller or other means, makes the upper sides (T1, T2) substantially horizontal and ready for the subsequent welding.

The end portion (3) is preferably though not necessarily conical and is connected to the conical portion (2) at the vertex section (23). The conical conformation of the end portion (3), the inclination of which, with respect to the rotating axis (Z), is opposite with respect to that of the conical portion (2) enables reducing the peaks of pressure which can occur at the vertex section (23) and at the edge of the upper side (T1). Furthermore, the conical conformation of the end portion (3) facilitates overall the machining of the surface of the roller. The angle included between the tapers of the conical portion (2) and of the end portion (3) is preferably but not necessarily greater than or equal to a right angle. This enables obtaining the advantages connected with the conical conformation of the end portion (3), maintaining a solid rest for the edge of the upper side (T1).

Preferably, though not necessarily, the shaped roller has shoulders (21, 31), i.e. zones located at the ends of the roller, having a cylindrical shape.

The operating unit according to the present invention comprises two shaped rollers (1), positioned with the end portions (3) thereof facing each other, i.e. positioned with the end portions facing towards the longitudinal direction (Y) and towards a vertical plane containing the longitudinal direction (Y). The two shaped rollers (1) are illustrated with the rotating axes (Z) thereof aligned. This solution enables reducing the dimensions of the operating unit along the longitudinal axis (Y). However the two shaped rollers (1) might also be staggered with respect to one another.

The shaped rollers (1) are arranged so that the upper sides (T1, T2) of the profiled element are in contact with the conical portion (2). As already mentioned, as they enter into contact with the conical portion (2) of the rollers (1), the upper sides (T1, T2) assume an inclination that is substantially coincident with the taper of the conical portion (2). As already mentioned, the shaped rollers (1) of the various operating units have a taper that gradually decreases in the advancement direction of the profiled element, so as to bring the upper sides (T1, T2) in a position progressively closer to the horizontal position.

The operating unit can be provided with adjustment means to allow the movement of the shaped rollers (1) along one or more horizontal directions and/or along a vertical direction. For example, the adjustment means can enable the nearing or distancing of the rollers (1) along a horizontal direction parallel to the rotating axes and/or a displacement of the rollers (1) along a direction parallel to the longitudinal axis (Y). The adjustment means are not illustrated in greater detail as they are known to a person skilled in the sector. The possibility of adjusting the position of the shaped to rollers (1) enables varying the shape and section of the profiled element (P), and varying the progression of the bending of the profiled element (P).

The operating unit (M) according to the present invention can be further provided with a lower roller (11), arranged to come into contact with the lower side (B) of the profiled element. The lower roller (11) is inclined in accordance with the inclination that it is desired to obtain for the lower side (B) of the profiled element. In the illustrated case the lower roller (11) is cylindrical and is arranged with the rotating axis horizontal. Adjustment means can be predisposed to enable the movement of the lower roller (11) along one or more horizontal directions and/or along a vertical direction, in order to enable various sections of the profiled element (P) to be obtained. In this case too, the adjustment means are not illustrated in greater detail as they are known to a person skilled in the sector. Preferably, though not necessarily, a lower roller (11) is interposed between two consecutive operating units (M).

The operating unit (M) according to the present invention can further comprise a pair of lateral rollers (12, 13), arranged to come into contact with the sides (S1, S2) of the profiled element. The lateral rollers (12, 13) can have a conical or cylindrical conformation (respectively FIGS. 4 and 5); in the latter case with an inclinable and adjustable rotating axis. As they enter into contact with the surface of the lateral rollers (12, 13), the sides (S1, S2) assume an inclination that substantially coincides with the taper of the lateral rollers (12, 13), in the first case, or substantially coincides with the inclination of the lateral rollers (12, 13) in the second case. Owing to the conformation of the shaped rollers according to the present invention, and in particular owing to the presence of the end portions (3), the action of the lateral rollers (12, 13) on the sides (S1, S2) of the profiled element is significantly more precise than in the present operating units. In fact, as already mentioned, each end portion (3) defines a reaction point for the edge of an upper side (T1, T2), which cannot therefore slide on the conical surface of the roller. This enables the lateral rollers (12,13) to press on the sides (S1, S2) in a uniform manner, given that the sides (S1, S2) cannot flex (this is because of the block of the upper sides (T1, T2) due to the end portions (3)). In this way, the sides (S1, S2) exactly copy the inclination of the surface of the lateral rollers (12, 13), enabling the precise realising of the predetermined radii of curvature on the corners of the profiled element (P).

The lateral rollers (12, 13) of the various operating units have a taper or inclination that gradually decreases in the advancement direction of the profiled element, up to becoming substantially cylindrical or vertical. This enables bringing the sides (S1, S2) into a substantially vertical position. Adjusting means (not illustrated as known to the skilled person in the sector) can be arranged to enable a displacement of the lateral rollers (12, 13) along one or more horizontal directions and along a vertical direction. The possibility of adjusting the position of the lateral rollers (12, 13) enables varying the shape and dimensions of the cross-section of the profiled element (P), and varying the progression of the bending of the sides (S1, S2), increasing the flexibility of the line and making it substantially universal (within a wide range of sections realisable for the profiled element).

The various rollers mentioned and described can be motorized or idle, in a known way for the technical expert in the sector, according to the effective production needs. 

1. A shaped roller for a profiling line, characterised in that it includes a conical portion (2) and an end portion (3), concentric respect to a rotating axis (Z), wherein the conical portion (2) is equipped with a vertex section (23), and wherein the end portion (3) has greater diameter than the vertex section (23) that defines a shoulder from the surface of the first conical portion (2).
 2. The shaped roller according to claim 1, wherein the end portion (3) is conical and connected to the conical portion (2) at the vertex section (23).
 3. The shaped roller according to claim 2, wherein the angle included between the tapers of the conical portion (2) and of the end portion (3) is greater than or equal to a right angle.
 4. An operating unit for a profiling line arranged to receive at the inlet a profiled element that has a cross section defined by a lower side (B), two sides (S1, S2) and two upper sides (T1, T2) sloped upward so as to be converging towards each other, characterised in that it includes two shaped rollers (1) according to claim 1, positioned with the end portions (3) facing each other and positioned in such a way that the upper sides (T1, T2) of the profiled element are in contact with the conical portion (2).
 5. The operating unit according to claim 4, wherein the end portions (3) are arranged to come into contact with the end edges of the upper sides (T1, T2).
 6. The operating unit according to claim 4, including adjustment means to allow the movement of the shaped rollers (1) along one or more horizontal directions and/or along a vertical direction.
 7. The operating unit according to claim 4, including a lower roller (11), arranged to come into contact with the lower side (B) of the profiled element.
 8. The operating unit according to claim 4, including two lateral rollers (12,13), arranged to come into contact with the sides (S1,S2) of the profiled element.
 9. The operating unit according to claim 8, wherein the lateral rollers (S1,S2) are conical.
 10. The operating unit according to claim 8, wherein the lateral rollers (S1,S2) are cylindrical, with a rotating axis that is sloped and adjustable relative to the vertical axis. 